Isoform-Selective PAD2/PAD4 Substrates with Unnatural Amino Acids Enable Cellular Peptidylarginine Deiminase Activity Profiling and Reveal Vimentin Citrullination Effects in Macrophages.

ABSTRACT: Peptidylarginine deiminases (PADs) catalyze the calcium-dependent conversion of arginine to citrulline, which affects diverse cellular processes. Among the human PAD isoforms, PAD2 and PAD4 are particularly relevant because of their distinct tissue distributions and substrate preferences. However, the lack of isoform-selective substrates has limited our ability to discriminate between their activities in biological systems. In this study, we developed PAD2- and PAD4-selective fluorogenic peptide substrates using the Hybrid Combinatorial Substrate Library (HyCoSuL) strategy, which incorporates both natural and over 100 unnatural amino acids. Substrate specificity profiling at P4-P2 positions revealed that PAD2 tolerates a broader range of residues, particularly at the P2 position, whereas P

SUBMITTER: Gorzen O 

PROVIDER: S-EPMC12509316 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature